Adjustable Current Source – 0 to 1A
This voltage-to-current (V-I) converter delivers a well-regulated current to a load. The circuit accepts an adjustable input voltage from Trimmer potentiometer PR1 and converts it to an output current from 0A to 1A.
This voltage-to-current (V-I) converter delivers a well-regulated current to a load. The circuit accepts an adjustable input voltage from Trimmer potentiometer PR1 and converts it to an output current from 0A to 1A. The current is regulated by feeding the voltage across a low-side, current-sense resistor R9 back to the OPAMP. The output Darlington pair allows for higher current gain. Feedback components R8 and C6 provide frequency compensation to ensure the stability of the circuit during transients. They also help reduce noise. R8 provides a DC feedback path directly at the current setting resistor, R9, and C1 provide a high-frequency feedback path that bypasses the NPN pair.
Features
- Supply 24V
- Output Current 0 to 1A (Adjustable)
- PCB Dimensions 41.59 x 30.48 mm
- 4 x 2.5 mm Mounting Holes
Connections
- CN1: Pin 1 = GND, Pin + Load Supply 24V DC
- CN2: Pin 1 = + Load Supply, Pin 2 GND
- D1: Power LED
- PR1: Current Adjust 0 to 1A
Schematic
Parts List
| NO | QNTY | REF | DESC | MANUFACTURER | SUPPLIER | SUPPLIER PART NO |
|---|---|---|---|---|---|---|
| 1 | 1 | CN1 | 2 PIN SCREW TERMINAL PITCH 5.08MM | PHOENIX | DIGIKEY | 277-1247-ND |
| 2 | 4 | U2,CN2,C5,R10 | DNP | |||
| 3 | 2 | C1,C3 | 100nF/50V CERAMIC SMD SIZE 0805 | MURATA/YAGEO | DIGIKEY | |
| 4 | 1 | C2 | 220uF/50V ELECTROLYTIC SMD | PANASONIC | DIGIKEY | PCE3921CT-ND |
| 5 | 1 | C4 | 10uF/35V CERAMIC SMD SIZE 0805 | MURATA/YAGEO | DIGIKEY | |
| 6 | 1 | C6 | 10PF/50V CERAMIC SMD SIZE 0805 | MURATA/YAGEO | DIGIKEY | |
| 7 | 1 | D1 | LED RED SMD SIZE 0805 | OSRAM | DIGIKEY | 475-1278-1-ND |
| 8 | 1 | PR1 | 100K MULTITURN TRIMMER POT | BOURNS | DIGIKEY | 3296Y-104LF-ND |
| 9 | 1 | Q1 | TIP142 TO247 | ON SEMI | DIGIKEY | TIP142GOS-ND |
| 10 | 3 | R1,R6,R7 | 0E SMD SIZE 0805 | MURATA/YAGEO | DIGIKEY | |
| 11 | 1 | R2 | 330K 1% SMD SIZE 0805 | MURATA/YAGEO | DIGIKEY | |
| 12 | 1 | R3 | 3.3K 5% SMD SIZD SIZE 0805 | MURATA/YAGEO | DIGIKEY | |
| 13 | 1 | R4 | 49.9K 1% SMD SIZE 0805 | MURATA/YAGEO | DIGIKEY | |
| 14 | 1 | R5 | 249E 1% SMD SIZE 0805 | MURATA/YAGEO | DIGIKEY | |
| 15 | 1 | R8 | 10K 1% SMD SIZE 0805 | MURATA/YAGEO | DIGIKEY | |
| 16 | 1 | R9 | 0.01E 1% SMD SIZDE 2512 | MURATA/YAGEO | DIGIKEY | |
| 17 | 1 | U1 | OPA197 SOT23 | TI | DIGIKEY | 296-47813-1-ND |
| 18 | 1 | Z1 | 2 PIN SCREW TERMINAL PITCH 5.08MM | PHOENIX | DIGIKEY | 277-1247-ND |
Connections
Gerber View
Photos
